Luxury vehicle maker Benz’s China joint venture Beijing Benz will recall 1,925 Mercedes-Benz vehicles as of May 31 due to defective airbags.

The move involves its C-class sedans and GLC sport utility vehicles produced between January 27 and March 26, 2018, according to information on China’s State Administration for Market Regulation.

The knee airbags for the driver may not provide effective protection as the supplier of vehicles used unqualified materials for the airbag, it said. It could increase the risk of injury to people in the vehicle in the case of an accident. Beijing Benz will replace the defective knee airbags free of charge for affected vehicles.

Since China began implementing the rule of recalling defective cars in October 2004, more than 1,800 recalls have been announced by automakers, involving over 69 million vehicles, Xinhua News Agency reported.